Human Anatomy Vol 1

lnternal jugular vein

Subclavian vein

Right brachiocephalic vein

Vena azygos

Superior vena cava

SUPEBIOH VENA CAVA, AORTA AND PULMONARY TRUNK

Left flrst rib

Left brachiocephalic vein

Costal cartilages

Left internal jugular vein

Brachiocephalic artery

Left subclavian vein

Left brachiocephalic vein

Left subclavian artery

Arch of aorta

Left pulmonary artery

Pericardium

Pulmonary trunk

Ascending aorta

Right atrium

Fig. 19.2: The superior vena cava and its relations

Right internal jugular vein ---

Right subclavian vein

Right brachiocephalic vein

Superior vena cava

Azygos vein

When the superior vena cava is obstructed above
the opening of the azygos vein, the venous blood
of the upper half of the body is returned through
the azygos vein; and the superficial veins are
dilated on the chest up to the costal margin
(Fig. 19.a). Blood from upper limb is returned
through the communicating veins joining the
veins around the scapula with the intercostal
veins. The latter veins of both sides drain into vena
azySos.
When the supericlr vena cava is obstructed below
the opening of the azygos veins, the blood is
returned through the inferior vena cava via the
femoral vein; and the superior veins are dilated
on both the chest and abdomen up to the
saphenous opening in the thigh. The superficial

vein connecting the lateral thoracic vein with the

superficial epigastric vein is known as the

thoracoepigastric v ein (Fig. 19.5).

o In cases of mediastinal syndrome, the signs of

superior vena caval obstruction are the first to

aPPear.

The aorta is the great arterial trunk which receives

oxygenated blood from the left ventricle and distributes

it to all parts of the body. It is studied in thorax in the

following three parts:

1 Ascending aorta.

2 Arch of the aorta.

3 Descending thoracic aorta.

Fig. 19.1: Surface marking of veins of thorax